Ocean acidification and its potential effects on marine ecosystems

Ocean acidification is rapidly changing the carbonate systemof the world oceans. Past mass extinction events have been linkedto ocean acidification, and the current rate of change in seawaterchemistry is unprecedented. Evidence suggests that these changeswill have significant consequences for marine taxa, particularlythose that build skeletons, shells, and tests of biogenic calciumcarbonate. Potential changes in species distributions and abundancescould propagate through multiple trophic levels of marine foodwebs, though research into the long-term ecosystem impacts ofocean acidification is in its infancy. This review attemptsto provide a general synthesis of known and/or hypothesizedbiological and ecosystem responses to increasing ocean acidification.Marine taxa covered in this review include tropical reef-buildingcorals, cold-water corals, crustose coralline algae, Halimeda,benthic mollusks, echinoderms, coccolithophores, foraminifera,pteropods, seagrasses, jellyfishes, and fishes. The risk ofirreversible ecosystem changes due to ocean acidification shouldenlighten the ongoing CO2 emissions debate and make it clearthat the human dependence on fossil fuels must end quickly.Political will and significant large-scale investment in clean-energytechnologies are essential if we are to avoid the most damagingeffects of human-induced climate change, including ocean acidification.